Author: blass uri
Date: 12:14:24 09/23/99
Go up one level in this thread
On September 23, 1999 at 09:43:20, Robert Hyatt wrote: >On September 23, 1999 at 09:24:43, Wayne Lowrance wrote: > >>On September 22, 1999 at 22:54:07, Robert Hyatt wrote: >> >>>On September 22, 1999 at 20:25:56, Howard Exner wrote: >>> >>>>On September 22, 1999 at 13:42:26, Robert Hyatt wrote: >>>> >>>>>On September 22, 1999 at 13:40:37, Robert Hyatt wrote: >>>>> >>>>>>On September 22, 1999 at 11:46:29, Howard Exner wrote: >>>>>> >>>>>>>Do any of the programs with endgame tablebases solve this position? >>>>>>> >>>>>>>8/6Bp/6p1/2k1p3/4PPP1/1pb4P/8/2K5 b - - id Pos 111 - ECM98H.EPD; bm b3b2 >>>>>>> >>>>>>>It looks too difficult for non tablebase programs. >>>>>> >>>>>> >>>>>>Crafty solves it, but it takes longer than I would like to see... 11 minutes. >>>>>> >>>>>>here is the output: (quad xeon with all the 5 piece ending databases). >>>>>> >>>>>> 15-> 1:46 -0.09 1. ... Kd6 2. Bf8+ Ke6 3. f5+ Kf6 4. >>>>>> Kb1 Bd4 5. Ba3 h6 6. Bb2 h5 7. Bxd4 >>>>>> exd4 8. Kb2 hxg4 9. hxg4 d3 10. Kxb3 >>>>>> d2 11. Kc2 >>>>>> 16 2:21 -0.17 1. ... Kd6 2. Bf8+ Ke6 3. f5+ gxf5 >>>>>> 4. gxf5+ Kf6 5. Bc5 h5 6. Kb1 Kf7 7. >>>>>> Ba3 Kf6 8. Kc1 h4 9. Bb2 Be1 10. Kd1 >>>>>> Bf2 >>>>>> (3) 16-> 4:07 -0.17 1. ... Kd6 2. Bf8+ Ke6 3. f5+ gxf5 >>>>>> 4. gxf5+ Kf6 5. Bc5 h5 6. Kb1 Kf7 7. >>>>>> Ba3 Kf6 8. Kc1 h4 9. Bb2 Be1 10. Kd1 >>>>>> Bf2 >>>>>> (2) 17 6:09 -0.26 1. ... Kd6 2. Bf8+ Ke6 3. f5+ Kf6 4. >>>>>> Ba3 Bd4 5. Kb1 Bc3 6. g5+ Kf7 7. f6 >>>>>> Bd2 8. Bc1 <HT> >>>>>> 17 11:26 0.00 1. ... b2+ 2. Kc2 exf4 3. Bxc3 f3 4. >>>>>> Be1 Kd4 5. Bf2+ Kxe4 6. Ba7 Kf4 7. >>>>>> Bf2 Ke4 >>>>>> (4) 17-> 11:42 0.00 1. ... b2+ 2. Kc2 exf4 3. Bxc3 f3 4. >>>>>> Be1 Kd4 5. Bf2+ Kxe4 6. Ba7 Kf4 7. >>>>>> Bf2 Ke4 >>>>>> >>>>>>Don't know whether it will fail high at 18 or not, however... >>>>> >>>>> >>>>>depth 18 analysis: >>>>> >>>>> (3) 18 13:55 0.31 1. ... b2+ 2. Kc2 exf4 3. Bxc3 f3 4. >>>>> Be1 Kd4 5. Bf2+ Kxe4 6. Ba7 b1=Q+ 7. >>>>> Kxb1 Kd3 8. h4 Ke2 9. h5 gxh5 10. gxh5 >>>>> f2 11. Bxf2 Kxf2 12. Kc2 Ke3 >>>> >>>>I tried this on CM6000 and Rebel 10c but stopped after 30 minutes(this >>>>on an AMD 233). The 11 minutes looks impressive to me. In your final analysis >>>>on move number 9 rather than capturing with gxh5 the winning move is g5, >>>>so that the black king can capture both of white's pawns. However in an actual >>>>game Crafty would no doubt see that when it reached that point in the game. >>>> >>>>My guess is that we won't see to many people posting that program X >>>>finds this one. Hope I'm wrong in this guess. >>>> >>>>Now I'm also wondering if tablebases will help here as after the initial >>>>exchanges there remain two pawns each on the king's side? >>> >>> >>>It was definitely probing tablebases during the search. The disk was very >>>active due to the captures... >> >>Yes, Hiarcs was probing table bases during its search as well. Hiarcs found the >>solution at the 21:04 minute mark and made the move shortly there after. The >>Table Base print out that followed the Hiarcs search listing was: >> >>=+ (-0.26) depth 13/30 00:21:04 72203kn, tb=12 > > >what does "tb=12" mean? My program did over 60,000 probes. If that means only >12 were done, something is not done right in Hiarcs... Hiarcs is different than crafty so you cannot say that something is wrong with it only because it does different number of probes. Maybe it does not call tablebases everywhere in the tree but only if it believe that calling tablebases is going to save time. If you are not close to the leaves of the tree then calling tablebases is clearly saving time because the time of search is bigger then time of probing but if you are close to the leaves then you lose time from calling tablebases and it is not clear to me if the perfect information that you get is more important then the time that you lose. Uri
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